Methods of manufacturing engineered wood products

Abstract

Methods for manufacturing an engineered wood product are disclosed. The method includes contacting at least part of a first set of wood pieces with a first resin; contacting at least part of a second set of wood pieces with a second resin, wherein the second resin is more washout resistant than the first resin; orienting the first and second set of wood pieces to provide a blanket of oriented pieces, the blanket of oriented pieces including a core layer formed of the second set of wood pieces sandwiched between a pair of face layers formed of the first set of wood pieces; steam preheating at least a portion of the blanket of oriented pieces; and curing the first and second resins by exposing at least a part of the blanket of oriented pieces to at least one of an elevated temperature, an elevated pressure, and radiant energy.

1 . A method of manufacturing an engineered wood product, comprising: 
 contacting at least part of a first set of wood pieces with a first resin;    contacting at least part of a second set of wood pieces with a second resin, wherein the second resin is more washout resistant than the first resin;    orienting the first and second set of wood pieces to provide a blanket of oriented pieces, the blanket of oriented pieces including a core layer formed of the second set of wood pieces sandwiched between a pair of face layers formed of the first set of wood pieces;    steam preheating at least a portion of the blanket of oriented pieces; and    curing the first and second resins by exposing at least a part of the blanket of oriented pieces to at least one of an elevated temperature, an elevated pressure, and radiant energy,    wherein at least one of the blanket of oriented pieces and the steam preheating is configured to at least substantially minimize washout of the first resin.    
   
   
       2 . The method of  claim 1 , wherein the first resin includes at least one phenol-formaldehyde (PF) resin.  
   
   
       3 . The method of  claim 2 , wherein the at least one PF resin is in at least substantially liquid form.  
   
   
       4 . The method of  claim 2 , wherein the at least one PF resin is in at least substantially solid form.  
   
   
       5 . The method of  claim 2 , wherein the at least one PF resin includes one or more PF resins in at least substantially liquid form and one or more PF resins in at least substantially solid form.  
   
   
       6 . The method of  claim 1 , wherein the second resin reacts with water.  
   
   
       7 . The method of  claim 6 , wherein the second resin includes at least one isocyanate resin.  
   
   
       8 . The method of  claim 7 , wherein the at least one isocyanate resin includes methylene diphenyl diisocyanate (MDI).  
   
   
       9 . The method of  claim 1 , wherein at least one of the face layers has a weight per unit area before the steam preheating based, at least in part, on at least one of a target thickness for the product, a target density for the product, steam preheating time, and washout resistance of the first resin.  
   
   
       10 . The method of  claim 9 , wherein the weight per unit area of at least one of the face layers is about 0.2 to about 1.2 pounds per square foot (lbs/ft2) before the steam preheating.  
   
   
       11 . The method of  claim 10 , wherein the weight per unit area of both face layers is about 0.2 to about 1.2 lbs/ft2 before the steam preheating.  
   
   
       12 . The method of  claim 1 , wherein the blanket of oriented pieces includes a face-layers-to-core-layer weight ratio before the steam preheating based, at least in part, on at least one of a target thickness for the product, a target density for the product, steam preheating time, and washout resistance of the first resin.  
   
   
       13 . The method of  claim 12 , wherein the face layers to core layer weight ratio before the steam preheating is from about 5% to 95%, to about 40% to 60%.  
   
   
       14 . The method of  claim 1 , wherein the steam preheating is for a sufficient period of time to raise the temperature of at least a substantial portion of the core layer to a target core temperature based, at least in part, on at least one of a target thickness for the product, a target density for the product, and washout resistance of the first resin.  
   
   
       15 . The method of  claim 14 , wherein the sufficient period of time for the steam preheating is about 20 seconds to about 70 seconds.  
   
   
       16 . The method of  claim 15 , wherein the target core temperature is about 100° C.  
   
   
       17 . The method of  claim 1 , wherein the steam preheating is applied to at least a substantial portion of at least one of the face layers.  
   
   
       18 . The method of  claim 1 , wherein the steam preheating is applied to at least a substantial portion of the blanket of oriented pieces.  
   
   
       19 . The method of  claim 1 , wherein at least one of the steam preheating and curing is at least substantially performed in a continuous press.  
   
   
       20 . The method of  claim 1 , wherein at least a substantial portion of the wood pieces of the core layer and the face layers are oriented at least substantially lengthwise.  
   
   
       21 . The method of  claim 1 , wherein at least a substantial portion of the wood pieces of the core layer are oriented at least substantially perpendicular to at least a substantial portion of the wood pieces of the face layers.  
   
   
       22 . The method of  claim 1 , wherein at least one of the first and second sets of wood pieces includes wood strands.  
   
   
       23 . The method of  claim 1 , wherein at least one of the first and second set of wood pieces includes wood flakes.  
   
   
       24 . A method of manufacturing an engineered wood product, comprising: 
 contacting at least part of a first set of wood pieces with at least one PF resin;    contacting at least part of a second set of wood pieces with at least one MDI resin;    orienting the first and second set of wood pieces to provide a blanket of oriented pieces, the blanket of oriented pieces including a core layer formed of the second set of wood pieces sandwiched between a pair of face layers formed of the first set of wood pieces;    steam preheating at least a portion of the blanket of oriented pieces; and    curing the first and second resins by exposing at least a part of the blanket of oriented pieces to at least one of an elevated temperature, an elevated pressure, and radiant energy,    wherein the pair of face layers each has a weight per unit area of about 0.2 to 1.2 pounds per square foot (lbs/ft2) before the steam preheating.    
   
   
       25 . The method of  claim 24 , wherein at least a substantial portion of the wood pieces of the core layer and the face layers are oriented at least substantially lengthwise.  
   
   
       26 . The method of  claim 24 , wherein at least a substantial portion of the wood pieces of the core layer are oriented at least substantially perpendicular to at least a substantial portion of the wood pieces of the face layers.  
   
   
       27 . A method of manufacturing oriented strand lumber, comprising: 
 contacting at least part of a first set of wood strands with at least one PF resin;    contacting at least part of a second set of wood strands with at least one MDI resin;    orienting lengthwise the first and second set of wood strands to provide a blanket of oriented strands, the blanket of oriented strands including a core layer formed of the second set of wood strands sandwiched between a pair of face layers formed of the first set of wood strands;    steam preheating at least a portion of the blanket of oriented strands for a sufficient period of time based, at least in part, on at least one of a target thickness for the product, a target density for the product, and washout resistance of the first resin; and    curing the first and second resins by exposing at least a part of the blanket of oriented strands to at least one of an elevated temperature, an elevated pressure, and radiant energy,    wherein the pair of face layers each has a weight per unit area of about 0.2 to 1.2 pounds per square foot (lbs/ft2) before the steam preheating.    
   
   
       28 . The method of  claim 27 , wherein the at least one PF resin includes one or more PF resins in at least substantially liquid form and one or more PF resins in at least substantially solid form.  
   
   
       29 . The method of  claim 27 , wherein at least one of the steam preheating and the curing is at least substantially performed in a continuous press.